Functional disorders of the gastrointestinal tract are common and account for a very large number of medical consultations. On an annual basis approximately 30% of the western population experience such functional dyspeptic symptoms varying from mild indigestion to severe pain. The symptomatology may be due to an organic disease (for example peptic ulcer disease) or, more commonly, be without any known origin (i.e. absence of organic pathology in the upper gut as evidenced by various diagnostic procedures). In clinical routine the latter symptom-syndrome is commonly called "non-ulcer dyspepsia", "functional dyspepsia", or "non-organic dyspepsia". Current treatment of dyspepsia with unknown origin involves a variety of pharmacological principles, e.g. neutralization of gastric acidity or affecting the motility of the gut wall, some of which have doubtful efficacy and sometimes have severe side effects.
Dyspepsia due to peptic ulcer can be cured by intake of antacids and inhibitors of gastric acid secretion. Ulcer-like dyspeptic symptoms, also without mucosal pathology, usually respond to similar treatment. This sub-population of dyspeptic symptoms (acid-related dyspepsia) is thus defined by the symptom-relief in association with intake of neutralizing agents or of inhibition of gastric acid production by use of proton pump inhibitors or histamine H2-receptor antagonists. However, the former treatment is short-lasting and neutralizing drugs must be administered repeatedly during the day. The latter treatment has disadvantages of being expensive and exerting an impact on the gut physiology, as the antacid gastric conditions increase the risk for intestinal and/or systemic infections. Prokinetic drugs (such as cisapride) or anticholinergic compounds are other agents that are utilized to cure dyspeptic symptoms, usually with variable efficiency and high frequency of side effects. It follows that available drug regimens for treating dyspeptic symptoms are impaired by certain disadvantages.
The present invention relates to a new method of treating dyspepsia with unknown origin by pharmacological interference with the renin-angiotensin system (RAS).